this is what i came up with looking at other people i keep getting #invalid operation

=SUMIFS({2021 Sioux City Utility OSHA 300 Form Range 18}, {2021 Sioux City Utility OSHA 300 Form Range 1} <= DATE(2021, 1, 31), {2021 Sioux City Utility OSHA 300 Form Range 1}, >=DATE(2021, 1, 1))

the first range (range 18) is the #number of event days in a month, the second (range 1) is the initial day of the event. I want to add up the days per month per event.